The present invention relates to an equipment for forming a film on a substrate to be processed using a photochemical reaction. More particularly, the present invention pertains to an equipment for manufacturing semiconductor devices which is suitable for forming a flat insulation film on a substrate to be processed having a stepped circuit pattern produced thereon.
To cope with the need for an increase in integration density of LSI devices, circuits are increasingly formed with multi-stratification. In order to attain multi-stratification, it is necessary to employ a technique for flattening the upper surface of insulation film even when the circuit pattern of the lower layer has a step. As a means for this purpose, the biased-sputtering method is presently utilized. In this method, etching proceeds in an oblique part of the insulation film, while deposition proceeds on a flat part thereof, and the uneven insulation film is therefore flattened as the processing progresses (see "Biased-sputtered SiO.sub.2 film; its formation and characterization of film quality" by Tsunekawa, research report of the section of applied electronic solid state physics, No.404, 1984, p.30). In this method, however, discharge is utilized to form a flat insulation film, which disadvantageously involves a fear of the insulation film and an element thereunder being damaged by the impact applied thereto by the charged particles (see "Semiconductor World", Press Journal, November 1984, pp. 103 to 104).